Watercraft such as those known as "personal watercraft" have a hull which defines an engine compartment, and include a water propulsion device. An internal combustion engine is positioned in the engine compartment. An output shaft of the engine is arranged to drive the water propulsion device.
An air intake system provides air to the engine for use in the combustion process. The portion of the intake system associated with the engine draws air from within the engine compartment and delivers it to each combustion chamber thereof. The portion of the intake system associated with the watercraft includes one or more air passages leading from a point external to the hull through the hull into the engine compartment.
In addition, the watercraft includes a fuel system for supplying fuel to each combustion chamber of the engine. The fuel system includes a fuel tank positioned in the hull of the watercraft and a fuel pump delivering fuel from the tank to at least one charge former, such as a full injector, which introduces fuel to the engine.
Because the watercraft is operated in the water, water often enters the engine compartment through the air passages through the hull. This water may damage sensitive components, such as the fuel injector(s). In addition, water may be drawn directly into the air intake of the engine. When a throttle valve is positioned in the intake system of the engine, this water may cause the valve to corrode and stick, preventing it from operating properly.
In addition, the engine has an exhaust system associated therewith. Exhaust is routed from the engine through the exhaust system to a point external to the watercraft, typically into the body of water in which the watercraft is operating. In order to prevent the flow of water back through the exhaust system to the engine, a water lock is positioned between the discharge point and the engine. Because the water lock must handle hot exhaust, it is constructed of metal. Because the water lock is exposed to water, however, corrosion often significantly shortens the life of this component.
A watercraft arranged to overcome the above-stated problems is desired.